I have a project which measures temperature and humidity. After measurement the data should be send trough BLE.
I have one service for the sensor and two characteristics for humidity and temperature. On the MCP I see the service and the two characteristics.
The problem is, when I try to read the values of the sensor over MCP, I will always get 0 as value.
Here the set up for temperature:
Sensor.h:
uint32_t ble_fridge_send_temp(ble_fridge_t * p_fridge, uint8_t temp_value);
Sensor.c:
static uint32_t temp_char_add(ble_fridge_t * p_fridge, const ble_fridge_init_t * p_fridge_init)
{
ble_gatts_char_md_t char_md;
ble_gatts_attr_t attr_char_value;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md;
memset(&char_md, 0, sizeof(char_md));
char_md.char_props.read = 1;
char_md.char_props.write = 1;
char_md.p_char_user_desc = NULL;
char_md.p_char_pf = NULL;
char_md.p_user_desc_md = NULL;
char_md.p_cccd_md = NULL;
char_md.p_sccd_md = NULL;
ble_uuid.type = p_fridge->uuid_type;
ble_uuid.uuid = FRIDGE_UUID_TEMP;
memset(&attr_md, 0, sizeof(attr_md));
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
attr_md.vloc = BLE_GATTS_VLOC_STACK;
attr_md.rd_auth = 0;
attr_md.wr_auth = 0;
attr_md.vlen = 0;
memset(&attr_char_value, 0, sizeof(attr_char_value));
attr_char_value.p_uuid = &ble_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.init_len = sizeof(uint8_t);
attr_char_value.init_offs = 0;
attr_char_value.max_len = sizeof(uint8_t);
attr_char_value.p_value = NULL;
return sd_ble_gatts_characteristic_add(p_fridge->service_handle, &char_md,
&attr_char_value,
&p_fridge->temp_char_handles);
}
uint32_t ble_fridge_send_temp(ble_fridge_t * p_fridge, uint8_t temp_value)
{
ble_gatts_hvx_params_t hvx_params;
if (p_fridge == NULL)
{
return NRF_ERROR_NULL;
}
if ((p_fridge->conn_handle == BLE_CONN_HANDLE_INVALID) || (!p_fridge->is_notification_enabled))
{
return NRF_ERROR_INVALID_STATE;
}
memset(&hvx_params, 0, sizeof(hvx_params));
hvx_params.handle = p_fridge->temp_char_handles.value_handle;
hvx_params.p_data = &temp_value;
hvx_params.type = BLE_GATT_HVX_NOTIFICATION;
return sd_ble_gatts_hvx(p_fridge->conn_handle, &hvx_params);
}
main.c:
float temperature;
static void temp_write_handler(ble_fridge_t *p_fridge, uint8_t temperature_value)
{
uint32_t err_code;
err_code = ble_fridge_send_temp(&m_fridge,temperature);
APP_ERROR_CHECK(err_code);
}
I tried it also with sd_ble_gatts_value_set:
Sensor.c
uint32_t ble_fridge_send_temp(ble_fridge_t * p_fridge, uint8_t temp_value)
{
ble_gatts_value_t gatts_value;
memset(&gatts_value, 0, sizeof(gatts_value));
gatts_value.len = sizeof(uint8_t);
gatts_value.offset = 0;
gatts_value.p_value = &temp_value;
return sd_ble_gatts_value_set(p_fridge->conn_handle, p_fridge->temp_char_handles.value_handle, &gatts_value);
}
Why ble_fridge_send_temp(); will not send the value of the temperature?
From the MCP:
-ReadAttributeValue(13)
-Recieved Read Response, handle: 0x000B, value (0x): 01
What is missing/wrong ?
